A paving machine configured to operate in a paving direction (e.g., the centerline of the roadway or surface to be paved being parallel to the longitudinal axis of the paving machine) may incorporate a paving kit, dowel bar inserter, texturing device, or other attachment or accessory secured to a lateral (ex.—transverse) framework. The lateral framework of the paving machine may comprise individual frame members of tubular steel, generally perpendicular to the paving direction. The lateral framework may support a diesel engine, electrical generator or other similar power plant for propulsion and to supply power to components of the paving machine or additional accessories removably mounted to the lateral framework.
The lateral framework may additionally support a module for the machine operator, including a user interface for the machine's control system. An end car may support the lateral framework at its left and right ends. Each end car may in turn incorporate a leg (ex.—vertical support) at its front and aft ends. Each leg may then be coupled to a steerable crawler, so that the steerable crawlers as a group contact the ground and propel the paving machine in the paving direction (i.e., longitudinally). Steerable crawlers may contact the ground via a continuous crawler track. A steerable crawler may be configured to rotate around its attached leg (via manual, hydraulic, or electronic over hydraulic actuation) alone or in combination with other attached steerable crawlers. The paving machine may therefore operate in a variety of steering modes. For example, a four-track machine (including a forward and aft crawler on both left and right end cars) may operate in a front or rear steering mode whereby the two forward or two aft steerable crawlers rotate in unison. A coordinated steering mode may position each opposing pair of steerable crawlers (i.e., left forward/right aft, right forward/left aft) in parallel alignment so that the paving machine may rotate 360 degrees within its own dimensions. A crab steering mode may direct all four steerable crawlers to turn in unison, so that the paving machine may be easily oriented on line or positioned on another vehicle for transport. When in an operating configuration, all steerable crawlers (whether two-track or four-track) will be oriented longitudinally so as to propel the paving machine in the paving direction. When transporting the machine from one site to another (i.e., via flatbed truck or similar vehicle), a narrower machine configuration is preferred. Therefore, the paving machine may be converted to a transport configuration whereby the steerable crawlers are rotated to an orientation parallel to the lateral framework (and consequently perpendicular to the paving direction).
To allow for the narrowest possible machine configuration, a supporting leg may be pivotably connected to its respective end car. For example, when in an operating configuration, the forward and aft legs of an end car may be fully extended in front of or behind, and perpendicular to, the lateral framework of the paving machine via an arm structure or similar extension. Each leg of the paving machine may include a vertically adjustable column capable of raising or lowering the height of the machine (e.g., via hydraulic jacking). If the lateral framework is otherwise supported, the vertically adjustable legs may be used to raise the attached steerable crawlers above ground level. Consequently, if forward and aft legs are connected to an end frame by a pivotable arm structure, the paving machine may be converted to a narrower transport configuration by, for example: rotating the steerable crawlers to align with the lateral framework; raising the steerable crawlers off the ground while supporting the lateral framework; and pivoting the arm structures to minimize the overall width of the paving machine. However, generally the arm structures must be pivoted manually, and any turnbuckles or supports holding the arm structures in place must be disconnected and then reconnected into a new position, a time-consuming process resulting in additional downtime for the paving machine. Even if the arm structures are partially articulable by hydraulic cylinders or similar actuators, the actuators must still be manually disconnected in order to pivot the arm structures beyond the plane defined by the end frame. It may therefore be desirable to provide fully automatic rotation of pivoting arms, and the connected adjustable legs, from an operating configuration to a transport configuration, without the need for manual repositioning, disconnection, or reconnection of components.